Thanks for replying.
As I wrote above, the homescreen widgets selector page only offers ONE Poweramp widget - a 1x1 playlist widget. I presumed this was because I have the Poweramp trial installed on an SD card (formatted as internal storage). The Poweramp website Features page, the Play store Poweramp page, and a popup that appears after first start of Poweramp after installing all say that with Poweramp installed on an SD card the user HAS TO install the separate 'Poweramp Widgets Pack' to get Poweramp widgets; the on first Poweramp start popup offers a button to fetch the Widget Pack; and the Poweramp settings menu has a button to go to fetch the Poweramp Widgets Pack, all repeating the need for it. But the link to fetch it goes to a Play store page that should be the page of the Poweramp Widget Pack but instead says 'Not found'. So what has happened to it? if it's needed as the Poweramp website, Play store page, first-start popup and settings menu all say, why has it disappeared and where can I get it?
On the other matter, I am using the version of Poweramp downloaded from the Play store. About once every 24 hours, though at varying times, not a specific fixed time each day, Poweramp just disappears. I turn the screen on, scroll to the homescreen it was on and the icon has gone. I check and it is no longer installed, and I have to reinstall it from my Library panel in the Play store. This does not happen with any other App I've had on my phone, including any of the other dozen music player apps I've been working through trying - and specifically it doesn't happen with PlayerPro - which has just sat there as Poweramp does its daily uninstall as I experiment with both of them, trying to choose between them after dismissing all the others.
This is concerning - if it's not normal with the trial, then it likely would go on happening if I bought the unlocker. I was starting to think I would choose Poweramp rather than PlayerPro, but if I can't fix this then I'll have to go PlayerPro.