Hello there, i have been spending few days just to get open source mobile wallet on github, but still can find it..
How about BlueWallet,
https://github.com/bluewallet/bluewallet? Both Android and iOS version are up to date with decent amount of features.
What i am looking for is, that the system are using RPC api, without electreum..
Could you elaborate? Are you looking wallet which also offer RPC/API or wallet which use existing RPC/API (but not Electrum protocol)?