This sealant spray from the Lidl's sports brand is a convenient way to get rolling again after you suffer a puncture - without having to remove the tyre or inner tube! All you need to do is remove the object that caused the puncture, screw the sealant tube onto the open valve, pop off the protective cap and release the contents of the can into the inner tube. Use a regular pump to top up the tyre, if the pressure is too low.
It's certainly a lot less faff than messing around with tyre removal and inner tube repair/replacement, but this sealant is only claimed to work as an "emergency fix". Once you're home, replace the tube with a new one. At £4 a can, I'll be carrying one as a "last gasp" option if my spare inner tubes let me down.