Its the first time I pay more than 99 cents for an app and I would say this one is the best purchase I ever made even though it doesnt translate full sentences yet. More than a simple dictionary, many tools for learners. The pronunciation (speech) is very clear and looks similar to a real human voice.
Even more helpful when the Thai keyboard was installed on my phone; via >settings >general >international >keyboards and then switch languages with the little planet next to the space bar.
Jobastian about Talking Thai <> English Dictionary+Phrasebook, v1.6