Number 1 with a bullet
This is the gold standard of Thai -English - Thai Phonetic dictionaries and allows you to look up Thai words by English translation, Thai language script, and the sound of the word in Thai. As well, you can hear a real person pronounce every word in the dictionary and particularly helpful is the word inside feature as much of the Thai language is composed of compound words. You can also look up English translations of Thai words.
Ive used the pocket sized printed dictionary for years and this iteration is even better.
I live in Thailand and use this app every day. It does everything it promises and does it well.
Buy it now. This is a must have for everyone who even thinks they may need it and the price is small compared to its usefulness.
Rainwalk about
Talking Thai <> English Dictionary+Phrasebook, v1.3