I've been using the Wallis Style App (apart from the fact I use it online because I'm old skool you see) and I've been more impressed than I thought I would be! It just so easy. You say who you are (age/shape etc) and it suggests things to you and you get a chance to say 'nah don't like that don't show me stuff like this again' or 'OMG YES I WANT TO BUY YOU NOW' or you may not be quite as dramatic as I am about clothes.
For my final choice from the suggestions I was offered this jacket. (currently on offer for £56 down from £70). I've been after one for a long long time so I was in the 'OMG YES I WANT TO BUY YOU NOW' camp when it was suggested to me. My word of advice is to DOWNSIZE, it comes up big.
Navy coat, have you got one? If you want to log on to the Wallis site to try their style adviser service out then I cannot recommend it highly enough.