Writing a WordPress plug in is an art of its own, and I admire anyone that can do that and keep up with the continual technology that happens on a daily basis. Many write the plug-ins but it is far from the end of the story as these have to be updated and maintained. If WordPress updates, all the various plug-in owners need to check their codes are still in keeping with the integrity of the new core code.
Any bugs that might be found have to be fixed and a new release has to be issued to cover these alterations to code. These can definitely be a learning curve. Different things affect the way a plug in works, and if it is one website or many that are maintained can also make a difference. One tends not to think that this can make a difference, but it apparently can. I wouldn’t have though of that myself. To me if you have a plug-in on a website it should cover it all. However, apparently some programs look at you as an individual or a group and their coding is different for each. Thus you have to make allowances for this. Often you need the cooperation of other people to enable you to both find and fix the problem. This is a huge leap of faith on the part of these people as it means that you are giving someone you don’t really know access to the backend of your website.
One needs to realize people generally are lazy and won’t fix or reconfigure for themselves so this has to be taken into account in the update so it is only necessary for them to load the update not do any other work. You are also then helping those that basically don’t know what to do. Not everyone is computer literate.
Never assume anything. Always use the KISS method. Always number things in a consecutive manner so you can keep track of your various features and updates. It is important to test the update thoroughly and with as many types of websites as you can prior to releasing it to the public. This cuts back on how many bugs you have to fix after the release. You don’t want hundreds of people moaning at you. Make sure people know which version they are using so they can update to the right version when you release it, and you need to know what version they are running too.
Something I had never thought about but, which can apparently make a huge difference to the way a plug-in works is the fact of running it on a secure site. A https site that is. Now most of my sites run on this format, and I personally haven’t had a problem but obviously, that is because the bugs might have been fixed before I got the plug-in. I can see that it has to get in under the radar, as it were. You need to test both http and https as well as extensions and sub directories. Sub domains also need to be addressed.