We consider recovery from ptychographic measurements also known as Short-Time Fourier Transform phase retrieval. We study Amplitude Flow, Error Reduction and Ptychographic Iterative Engine algorithms and derive their convergence speed. In addition, Block Phase Retrieval algorithm and its modifications are studied. Furthermore, we consider blind ptychography and devise a version of Amplitude Flow with guaranteed convergence. Finally, some results are extended to polychromatic ptychography.