Available in various sizes at plant fairs and shows but do contact me to see if I have a little one to pop in the post. It'll be no more than £10 + £5 p&p

That's Iochroma with an I as in Iodine. You  can surely see the family resemblance to the much larger trumpet plants, the Brugmansia but the Iochroma are generally hardier and  much more generous in the production of flowers, albeit diminutive ones, throughout the growing season, a large adult plant producing hundreds in a year. Iochroma australe ( or australis)  is a pretty blue species Iochroma  almost fully hardy for cultivation in the UK. Popular with the Bees too.

Iochroma australe