Thanks for reaching out in the community. Our IOS app only supports basic Lucidchart diagram editing. When you select a line you will notice that there are two icons (the trash and the text icon). Depending on the path of the arrow a third icon will appear (a white box with a double sided arrow). This third icon allows you to shift the line, which ultimately alters the line path. You can also alter the line shape whether it is straight, curved, or angled by selecting the line, select "styles" at the bottom of the tool bar on the left hand side, and changing the "line shape". I hope this helps!