I am no expert but some of these leather dressing don't sound good. Then again this website is trying to sell their product.
Care of Fine Leather
We are lucky the LG G4 leather isn't going to be flexed like a wallet. This is what got me since I have the T-Mobile Light Brown;
" The majority of leather dressings are based on tallow or neatsfoot oil.Tallow, even kidney fat, contains salts which build up with repeated dressing and attack the leather fibres. Neatsfoot oil compounds, long recognized for damage to sewing, also weaken
and blacken the leather. Both these animal fats provide a culture for the growth of bacteria and fungus, and turn rancid, resulting in further attack on the leather. The more liquid formulations also evaporate quickly, leaving the leather dry and open to rapid deterioration by oxidation and mechanical break down."