I would like to create a simple mobile application using flutter that would create and sign a transaction and submit it through an API like Blockfrost to the network for which it will interact with a smart contract address.
Is there any supporting library or any approach that can achieve this?
If you are willing to use a javascript library (see https://stackoverflow.com/questions/66145501/how-to-use-a-js-library-and-a-js-function-in-a-flutter-mobile-app) then you can try the helios library: https://github.com/Hyperion-BT/Helios
Helios should be callable from within flutter as it doesn't have any dependencies and uses pure javascript (no wasm).
With helios.js you can build transactions (https://www.hyperion-bt.org/Helios-Book/api/building/index.html). Signing however is usually done by a wallet, and for submitting to blockfrost you would have the call the blockfrost endpoint directly.
helios.js also allows compiling smart contracts written in the Helios language, but you probably won't be needing that.
