Creating a watch-only electrum-ltc wallet for a coinomi litecoin wallet is done as follows:
Use electrum-ltc:
https://electrum-ltc.org/
Coinomi:
https://play.google.com/store/apps/deta ... omi.wallet
In coinomi, go to "Settings->Show recovery phrase"
Copy the recover phase into this tool:
https://coinomi.com/recovery-phrase-tool.html
If not you have a BIP39 passphrase, that should be entered as well.
Select "litecoin".
(If you look in the Derived Addresses list. The addresses there should match the addresses you have in coinomi)
Go to the Derivation Path and click BIP32
Select derivation Path m/44'/2'/0'
Copy the field "BIP32 Extended Public Key (addresses only)" to electrum-ltc.
In electrum-ltc, choose "File->Restore". "Restore a wallet or import keys"/"Standard wallet".
Enter the "BIP32 Extended Public Key".
Ready!
If you use the "BIP32 Extended Private Key" instead, you will be able to spend the coins using electrum-ltc.