Some of the best mobile games bring a surprise with them. Who thought that firing birds with a catapult would be such a huge success?Taking the somewhat abstract and packaging it up into a game leads to some fantastic results and packaging is exactly what today's App of the Day is all about. Yes, we\u2019re going shopping.Bag it!\nPlatform\nAndroid\n\nPrice\nFree \/ \u00a31.27\n\nWhere\nGoogle Play (free)\u00a0\/\u00a0Google Play (full)\nBag it!, as you'll guess from the name, is all about bagging-up your shopping. How this moved itself from checkout-aisle frustration to amusing time-waster on your Android phone is beyond us, but it seems to have worked.The concept of the game is to pack items into a bag. There are various different challenges you'll face along with way, with different objectives in different levels. For example, in some levels you'll have to pack the items with nothing getting damaged, in other levels the aim is to have as many breakages as possible.It sounds simple, but the result is a game that offers a great deal of variety. Packing and rotating the items gives a hint of a Tetris-type puzzler, but there are also combos to be grabbed along the way, with bonus points awards when you combine the eggs, or get OJ and milk together, for example.\u00a0To progress you need to have collected the prerequisite number of stars, awarded for successful completion of various aspects of the game, unlocking things as you go along.It sounds simple, but at times you'll be left scratching your head trying to figure out exactly what you have to do to avoid squashing your eggs. That's one of the things we like about Bag it!: it's simple in concept, but tricky enough to remain interesting.We also find outselves confused by the characterisation of various products. The milk looks rather grumpy while the orange juice flutters its eyelashes at you alluringly. We've never thought of OJ as sexy, but there's a first time for everything.There is a Lite and a paid-for version of the game, with the free version offering up a surprising number of levels to get your teeth into. The full game will cost you \u00a31.27, but offers more than 60 levels. The free version will give you a selection of levels in three different modes to get you hooked.