The volunteers of the Santa Monica Mountains National Recreation Area, who are the authors of this app, take accessibility very seriously. We have worked hard to make the app friendly to screen readers like VoiceOver and TalkBack. By default, screen readers generally announce the hidden "titles" on a page, and consequently we have made a lot of use of them in this app. If you've turned these off in the settings of your screen reader, you might consider turning them back on. It is worth noting that screen readers generally mangle the pronunciation of the "Botanical Latin" of plant scientific names. For that reason, we have tended to down-play the use of the scientific names, at least in these hidden titles.
We are aware that the half-dozen "Text Search" pages are very large and that they can be a problem for screen readers. Unless you have a fast device, it is probably best to avoid using a screen reader on these large pages because your device may become quite sluggish attempting to read them. Unfortunately, for an app built upon a web site, there is no simple way around this when searching through thousands of items. Fortunately, none of these pages are essential to the operation of the app, and they are all clearly labeled, so they should be easy to avoid.
Other accessibility features include simplifying the app's toolbar to allow for larger buttons, copious off-screen titles for screen readers, increasing overall text size and line spacing, streamlining text formatting, creating long descriptive link names, eliminating abbreviations when feasible and/or spacing out their letters to encourage screen readers to spell them out, providing alternate "Large Text" versions of some pages, giving the user the ability to choose different background and text colors, employing an accessible color palette, and pushing the maximum page zoom setting (i.e., the page magnification), past the point where the page layouts begin to look distorted, but with the advantage that the text is larger and easier to read. BTW, the app's toolbar adjusts itself based on your device's accessibility settings, but if you make an accessibility change, you will probably need to restart the WildFlower app for your change to show.
Beyond this, please let us know if there is anything else we can do to help you enjoy the Wildflower app. It is the product of thousands of hours of work on the part of the volunteers of the National Park Service. We want you to enjoy using it as much as we have enjoyed creating it.