A girl transmigrated but also went back in time. The first is when the original body went through bad things her parents passed away and her brother went missing so she got a fiancé but he betrayed her and killed her then she woke up before the incident and wanted to fix things but also realized she transmigrated. She later went to an auction where they were selling a smart phone. Nobody knew what it was so she won. As it turned out a really smart university student transmigrated here and created a smart phone using magic. It has basic functions like a camera and a notepad app. She opened the back to see if there was a battery it turned out the battery was super valuable. Anyways she also as it turned out later found her brother who was with some nobles and prince. She slowly started making things like lip balm and heat pouches and stuff. I remember it was her aunt and stuff who stole all her families fortune with a forged document.

Sounds like
Iris: The Lady and Her Smartphone

Yay thank you!!!