In Tesco currently there is a '2 for £2' offer on Schwartz Herb and Spice jars. The are usually £1.50 each.http://www.tesco.com/groceries/product/details/?id=257485607
If you use checkoutsmart app there is a 'buy 3 get £2.50 back' offer on the same products.
By combining both offers I got 6 jars (usually £9) for the princely sum of £1.
Submitted my reciept to checkoutsmart last night and can confirm I have been paid £5 cashback by lunchtime.