GRS X-Mas 2021 Development Update

Groestlcoin News
7 min readDec 22, 2021



This year has been filled with ups and downs in the entire market. Beyond the chaos of the price fluctuations, GRS has spent 2021 striving for greater adoption and more use-cases for GRS. Whilst reflecting on 2021, why not look back at our previous development updates:

From everyone at the Groestlcoin team, we hope you have a fantastic Christmas / Holidays and here’s to a prosperous new year!

The past 3 months — Adoption

19th December — GRS is supported on Coinsbee, via our fourth BinancePay integration!

10th December — GRS is supported on BitRefill, via our third BinancePay integration!

2nd December — GRS is accepted on the NGrave Hardware wallet!

26th November — GRS is now accepted on, offering quality bike gear worldwide!

19th November — GRS is accepted at The House of CO-KÝ, a fashion brand now accepting cryptocurrency!

18th November — GRS is accepted at, a fashion merchandise store dedicated to accepting cryptocurrency

17th November — GRS is accepted at, the one-stop-shop for buying Cannabis Seeds

12th November — GRS is accepted at Marley Tattoo and Piercing Studio in Porec, Croatia!

11th November — GRS is accepted at Toronto Business Lawyer JKleiman!

6th November — GRS got its second BinancePay integration with UQUID Digital Store

22nd October — GRS was accepted on Gamerall, purchase digital game skins with digital currency!

20th October — GRS was accepted at PitaBarcelona, an independent luxury watch maker in Barcelona!

13th October — GRS was accepted for payment on MonsterMegsHost web hosting

6th October — GRS accepted on PlayHubCasino

29th September — Chris P Thompson started the GRS History Book

Development Update

GRS Pay — Taproot Edition

What is GRSPay? And how to use it.


  • Taproot support
  • Specify default payment method through UI and Greenfield API
  • Disallow cancelling payment request when “Allow payee to create invoices in their own denomination” is not enabled
  • Support custom currencies for Pay button generator
  • Show total balance on wallets list
  • Add ability to set invoice status from details page
  • Add ability to accept tips in POS terminal
  • Add ability to wipe all the transactions of a wallet for admins
  • Allow User to delete own account
  • Allow email notifications when creating invoices from Web UI
  • Greenfield: Provide negative undue when overpaid.
  • Support top-up invoices in apps
  • Support Lightning in Pull Payments.
  • Support LNURL and Lightning address in Pull Payments
  • Add boolean overPaid to the invoice settled webhook
  • Ability to display and update the appname in crowdfund and PoS
  • Add ability to require refund email from app level
  • Azerbaijan support for the checkout
  • Upgrade to Bootstrap 5.1.3

C-Lightning v0.10.2

What is C-Lightning? And how to use it…


  • Payments can now be retried without affecting the status of prior attempts.
  • The route selection will now use the log-propability-based channel selection to increase success rate and reduce time to completion.
  • Close now reports the feeranges each side enforced, which allows users to determine which side caused a high or low feerate.
  • Removal of old HTLC information and vacuuming shrinks large lightningd.sqlite3 by a factor of 2–3.
  • setchannelfee now has a grace period during which both old and new fee policies are considered. This prevents a fee update from making the channel unusable until the update propagated.
  • We now perform quick-close if the peer supports it.
  • We send regular pings to detect dead connections (particularly for Tor).
  • Errors returning a channel_update no longer return an outdated one.
  • Anchor output mutual close allow a fee higher than the final commitment transaction.
  • Plugins now are notified about an upcoming shutdown, allowing them to store data and clean up before exiting.
  • The datastore API (datastore, deldatastore, and listdatastore) exposes a simple key-value store, allowing plugin authors to store data in the c-lightning database.
  • ping now only works if we have a channel with the peer.
  • Relaxed the sqlite3 version match requirements to be at least a minimum version and a major version match

Groestlcoin Spark v0.3.1 (Windows, Linux, Mac OSX, Android)

What is Groestlcoin Spark? And how to download it.


  • BOLT12: Send payments using BOLT12 offers (including support for any amounts, quantities, fiat denomination and sending a payer_note to the payee). Requires c-lightning v0.10.1+ with experimental-offers enabled
  • BOLT12: Create reusable BOLT12 offers to receive multiple payments (basic support only). Requires c-lightning v0.10.1+ with experimental-offers enabled.
  • BOLT12: Pull payments using BOLT12 withdrawal offers (send_invoice=true). Requires c-lightning v0.10.1+ with experimental-offers enabled.
  • UI: Non-blocking payments with paystatus tracking
  • Payments are now sent in the background without blocking the UI, with pending/failed payments shown in the homepage payment history.
  • UI: Improve the main screen initial loading times
  • Pay/Request can now be used immediately, without waiting for the wallet’s data to load first.
  • UI: Always display payment amounts in USD terms too
  • UI: Improved error reporting and display
  • Fix: Properly display the NoScript message on Firefox
  • Update clightning-client to v0.1.4
  • Use newaddr all to avoid creating new addresses when switching types
  • This raises the minimally supported c-lightning version to v0.7.1.
  • Reproducibility: Due to changes in third-party dependencies, the Android apk build and the Windows portable runner are no longer reproducible, while the Linux AppImage now is.


Audio2bip39 is a fantastic tool that allows users to generate a BIP39 mnemonic phrase from an audio recording.


  • Supports 24-word phrases
  • Open Source

Available at: but as always, we always recommend hosting your own version using the source code:

Groestlcoin BlueWallet v6.1.9 — iOS and Android

What is Groestlcoin BlueWallet? And how to download.

What’s New?

  • ADD: camera on main screen
  • ADD: Shortcuts on Scan button long press
  • FIX: Set the first launch flag (issue with disappearing wallets)
  • ADD: Catalan and Slovak translation
  • ADD: custom success animation to onchain transactions
  • ADD: fiat input for receive & send
  • ADD: Fee details to lighting invoice
  • ADD: Entropy via dice rolls and coin flip
  • ADD: Exclude wallet transactions
  • ADD: Detect language automatically
  • ADD: Launch screen dark mode
  • ADD: Dark Mode
  • ADD: support importing watch-only in groestlcoincore format fingerprint/derivationxpub (wallet descriptors)
  • ADD: Split for large devices
  • ADD: Export file option
  • ADD: KES, NGN, TWD, ARS, ADD: TZS, ANG and AWG, UYU, Philippines Peso, Turkish Lira Currencies
  • ADD: Import LNDHub from QR
  • ADD: Electrum server import from QR
  • ADD: Privacy Settings Screen
  • ADD: Clipboard read opt-out
  • ADD: Support lnurl fallback scheme
  • ADD: Market Widget for iOS 14
  • ADD: Large iOS widget
  • ADD: Price Current/Previous Widget
  • ADD: Allow image for importing wallet
  • ADD: Coin Control
  • ADD: New languages: Bulgarian, Polish, Welsh, Slovenian & Hebrew
  • ADD: Multisig Vaults
  • ADD: Create Multisig Vaults
  • ADD: Import Multisig Vaults
  • ADD: Vaults Backup
  • ADD: Coordination Backup
  • ADD: Manage/edit Keys
  • ADD: Share co-signers
  • ADD: Quorum setup
  • ADD: Choose address type
  • ADD: Persian language
  • ADD: Help section and tips to Vaults
  • ADD: enable batch-send on multisig wallets
  • ADD: Easily share a Vault key with QR code
  • ADD: How many signatures can this Vault make
  • ADD: Electrum servers history — fast connect
  • ADD: Ability to set servers via QR code scanning
  • ADD: CoinControl multi-selection
  • ADD: iOS 14.5 support
  • ADD: Electrum-GRS JSON import support
  • ADD: Offline Signing and Cold Storage
  • ADD: Encrypted Message sign/verify
  • ADD: Allow send MAX and BATCH for all wallet types
  • ADD: Tor support
  • ADD: Hierarchy Navigator (List of addresses)
  • ADD: Slip39 wallets (Shamir’s Secret Sharing)
  • ADD: PSBT for all HD watch-only wallets

GRS RPC Explorer v3.3.0 — Mainnet, Testnet, and now Signet!

What is GRS RPC Explorer? And how to use it.

What’s New?

  • Signet support!
  • New tool for viewing the UTXO Set: /utxo-set
  • New API actions:
    — /api/address/yourAddress
    — /api/mining/next-block
    — /api/mining/next-block/txids
    — /api/mining/next-block/includes/:txid
    — /api/mining/miner-summary
  • Major fixes for data displayed in /tx-stats tool
  • /node-details: Include coinstatsindex status
  • Support querying UTXO Set even with slowDeviceMode=true, if coinstatsindex is available
  • Fix for difficulty adjustment estimate
  • /difficulty-history: Support for viewing different time ranges
  • When viewing unconfirmed transaction details, show an info dialog if the transaction is predicted to be confirmed in the next block
  • Performance improvements:
    — Fix for performance degradation over time due to slow “estimatedSupply” function
    — Homepage speedup by making “Estimated Next Block” data load asynchronously
    — Caching for /difficulty-history data
  • Unicode formatting for OP_RETURN and other similar data (with ascii+hex accessible via toggle)
  • New .env options for setting defaults (see .env-sample for details):
    — BTCEXP_DISPLAY_CURRENCY (grs,gro,local)
    — BTCEXP_LOCAL_CURRENCY (usd,eur,gbp)
    — BTCEXP_UI_TIMEZONE (utc,local)
    — BTCEXP_UI_HIDE_INFO_PANELS (true,false)
  • Support for displaying timestamps in local timezone (by using browser default, or setting a manual offset)
  • Cleanup treatment of locktime on transaction details pages
  • Unique favicon color based on the active network (mainnet=blue, testnet=black, signet=orange, regtest=gray)
  • Lots of minor styling improvements
  • Error handling improvements
  • Fix for /api/quotes/all
  • Performance log admin page at /admin/perf-log
  • Updated dependencies

Blockbook — Signet Version

What is Blockbook? And how to use it.

What’s New?

  • New version to use with the Signet network has been released!


For help and support with any Groestlcoin products, or just for a discussion or chat, please visit our social channels where the community will be more than welcome to help!



Everywhere Else…

For a full list of our social channels, please visit this medium article which lists every social channel:

Alternate News Link:

Thank you to everyone who has contributed to these developments. On to the next development update on 22nd March 2022!