Hi guys,
If you're looking for a free tower defense fix then this is a pretty fun download. It does have in app purchases but you should have a good deal of fun without having to ever buy anything.
Cheers
From Link:
The outcome of the war is in your hands!
Toy Defense 2 is the long-awaited sequel to the multi-million-download hit Toy Defense! Set in WW2, this action/strategy game is packed with more levels, amazing new features, a big selection of fighting units for each world, and more intense action than ever.
Take part in various missions in a range of theaters of war, from the picturesque beaches and forests of Normandy to the deserts of northern Africa. The most epic battles of WW2 await you!
Recruit, upgrade, and manage your troops to create your own powerful army! Defend your base, fight off invading enemies, and develop your own winning strategy!
GAME FEATURES:
- Classic tower defense gameplay with excellent level design and stunning artwork
- 84 levels of action-packed gameplay across 3 worlds
- Masterful reconstruction of the most decisive battles of WW2 – Operation Crusader, the Battle of Stalingrad, and Operation Overlord
- A set of unique combat units for each world inspired by real weapons and vehicles used in WW2
- Unlockable upgrade tree with multiple improvements for each unit
- New amazing power-ups to aid you in battle
- Unlimited potential for collecting hero units
- A brand new in-game notification center to keep you up to date with special offers, game events, upcoming updates, and much more
Maybe mention iOS in title.