Bluewallet and Electrum wallet are my top 2. Bluewallet has a decent UI/UX compared to Electrum but both wallet are reliable in terms of watching specific address.

Bluewallet is the best answer for me since you are just looking for a wallet to watch address. Bluewallet only sucks sometimes on updating the recommended transaction fee when sending Bitcoin but the rest of its feature is superb like Electrum but better design.