Here is the learning roadmap of Block chain for Mobile Developers

Theory and concepts
https://www.youtube.com/playlist?list=PLsyeobzWxl7oY6tZmnZ5S7yTDxyu4zDW-

Ethereum
https://ethereum.org/en/
https://youtu.be/itUrxH-rksc

HyperLedger
HyperLedger Besu
https://www.youtube.com/watch?v=1Y3nI8Mos_I&t=39s Besu Free gas
https://besu.hyperledger.org/en/stable/HowTo/Configure/FreeGas/ Besu consensus algorithms https://besu.hyperledger.org/en/stable/Concepts/Consensus-Protocols/Overview-Consensus/ Prove of Authority(POAs) https://besu.hyperledger.org/en/1.2.1/Consensus-Protocols/Comparing-PoA/

Solidity
https://soliditylang.org
https://youtu.be/ipwxYa-F1uY

HyperLedger
https://www.youtube.com/watch?v=iTV89Tqfmgk

Practicle Project

Build Block chain in 15 mins

https://youtu.be/baJYhYsHkLM

(For Android & Java)
https://boemo1mmopelwa.medium.com/implementing-etherium-blockchain-in-android-with-web3j-485ea0747088
https://medium.com/@pacs_IT/an-ethereum-api-for-android-app-developers-revision-and-whats-to-come-eb5488fc3adb

(For Flutter)
https://techblog.geekyants.com/developing-blockchain-applications-with-flutter
https://www.geeksforgeeks.org/flutter-and-blockchain-hello-world-dapp

https://www.youtube.com/watch?v=3Eeh3pJ6PeA
https://www.youtube.com/playlist?list=PLVL9I5xQTSjEXxmjUC-RjQq-yCGZfp9GF

My Done Projects
https://github.com/Rubywai/flutter_ethereum_blockchain https://github.com/Rubywai/flutter_ethereum_todolist_app

Important facts to know
Differences between Coin and Token
https://www.quora.com/What-is-the-difference-between-a-coin-and-a-token

ERC 20 Token Solidity Code https://github.com/rubywai/ERC20token