I try to learn my songs, but I do have a problem retaining those which I don't sing very often, so I take my iPad to singarounds etc., but try to use it as little as possible.

If I'm 'appearing', either solo or with the band, I have the iPad mounted on my mic stand and use it for my set lists (far better than writing on the back of one's hand, or trying to read a scrap of paper on the floor!). The beauty is that Onsong displays the lyrics to each song in the set-list, in the correct order, so if I 'dry' (and it happens more and more frequently as my 67 year-old brain farts more and more readily) I have a lifeline.

I have no problems with an aide-memoire being used by anyone - far preferable to squirming with embarrassment at a singer's discomfiture during that seemingly-interminable period when he or she is frantically trying to remember the forgotten lyrics, often in vain! But I dislike it intensely when people have clearly made absolutely no attempt to memorise any of their material, and read every line of every song, head down, eyes glued to their loose-leaf binder, and making no attempt to make even the briefest of eye contact with their audience.