I think this was the first gel liner easily available in UK stores, its currently £7.99 in Boots and as it claims it is a gel / cream consistency.
The black is deeply pigmented and it does last. Haven't tested it out for 24 hours but at 20 hours it was still in place. With a primer this doesn't transfer but without one it does a little bit, but this is a problem I often have with eye liners. Stays put on the waterline well.
You get a eyeliner brush which is flexible but firm enough for lining. Its flattened so you can easily do fine or thick lines.
£7.99 - Boots