If one does coding on Android, one might already know Hacker’s Keyboard app.
The suggested punctuation row is very helpful Despite the name, it is open source and does even not require Internet permission. It means what we have entered should be stored locally only.
When using with Code Editor or Termux, no doubt, Hacker’s Keyboard is one of the best free keyboards.
The best tip when using it is to use its suggested punctuation feature as an extra key row for coding, chars.
Here is my phone Hacker’s keyboard setting which produced the above-suggested row.
Go to Hacker’s Keyboard Setting > Suggested Punctuation
For example:
=`K#:(~)!/?_
You can use Ctrl + these chars. It also works!