Writing In Scale

 
I've never been one to write in scale but I thought I'd try.
The reason is that I'd like to be able to work out a melody to a new tune I'm writing. Thing is it tougher than it looks. Knowing the scale is the easy part and I have an app that'll show me all the chords in the scale. Unfortunately that app isn't conducive to writing tunes. I used an app that was supposed to suggest chords in a scale but that let me down by producing a double b and so that approach was abruptly halted.
My new approach is to write as I always have done, without a key, producing chords that I like. What I'll do afterwards is to change the out of key chords into in key chords while trying to keep the same structure. It has to be easier than limiting myself from the start.
Write free, knock into shape later is my new mantra.
Let's hope it works.