Here is another strategy video for my favourite iOS game Strategery. This video if for breaking through static borders in the mid to late game. Use this technique in preference to just creeping the border forward to end the game quickly or when you must come from behind to win. I used the finger to win a game where I only had about one third of the regions to the other opponents two-thirds. A disadvantage to that extent is a near certain loss if you stick with a "border creep" strategy. So, give your enemies the finger!
The finger can also useful in non-border reinforcement games - though the specifics of the opportunity are less likely to occur. Those specifics are; strong border (both) with a weak hinterland reachable by a break through.
See my other article: Strategery review, hints, tips, guide for more general info about the game and tips on how to play other modes.