Patchou, as you said, the very existence of this thread proves that you're different than greedy software companies who don't care about their users. This "human" quality is exactly what many other programs lack, I think.
Messenger Plus! is a very unique project: it manages to combine freeware + user attentiveness like a small open source project, together with a long-term commitment to the development of the software and the users, which is only possible due to the honest, "human" use of a sponsor.
Considering you're the only one behind this software, I find it admirable that you managed to keep it alive. It was only possible through the vast support you gained from your users, which you wouldn't get if you weren't so "human".
I think that in any aspect of life, being honest and attentive is just as important as being skilful, and you've proved that. I'm glad this software is in your hands.
Best of luck to you and your wonderful project!