making an LED flicker (probably need attiny help)

I want to make a single 0603 LED flicker, and keep everything as small as possible. 

One thing I tried was buying one of those dollar store flickering LED candles and using the light from it as my flicker circuit.  It's the LED itself that flickers, not a separate circuit.  I couldn't find any where the circuit was a separate chip.  I can't use this light as my light because they only come in yellow (I need white) and it's too large to fit in the hole where I want the light.  So I painted the LED black and attached it to my battery.  Now my actual project LED did flicker, but the other light was draining all my battery power so my main light was a bit dim and died quickly.  So sadly this $1 easy flicker method doesn't quite work.  Unless somebody knows how to zap the light without killing the flicker thingy.  Is that even possible?  I've no idea how those flickering LEDs work.

So I'm thinking I need to look at using an attiny.  I've read that the attiny9 or attiny10 are the smallest.  But I've no idea how to program them.  Do you guys think this is my best option?  If so, can somebody point me at a tutorial for what I need to program these?  Or does anybody sell them pre-programmed?  Thanks.