Notes Collector has a very similar user interface (look and feel) to Timestamped Field Notes. The primary difference is that Notes Collector is built upon a cloud database, and all data is synchronized to the cloud (and hence to your other devices), whereas Timestamped Field Notes is built upon a local / private database. Whereas Timestamped Field Notes allows local data to be stored in Google Drive, Notes Collector automatically synchronizes whenever online.
Notes Collector is available on iOS and Android.
Learn more about Notes Collector.