Lidl have got their little LED backup bike lights in again. I think they are excellent value and always handy to carry if there is any chance of coming back after sunset or in poor visibility. I bought another pair for the price of ... £1.79!
The front light is definitely 'to be seen by' rather than any use to light up the road. Both lights have steady and conventional flashing modes, but they also have a very eye-catching 'burst flashing mode'.
I will probably use 2 pairs on my bike so one pair can act as backup for the other.
The lights use 2xCR2032 type batteries each. Those batteries can be quite expensive if you pay full price for single cells but you can get them cheap on
eBay - e.g.
20 for £2.49.