You could take your digital camera along with you but set its meter to centre-weighted average. The high-tech matrix/evaluative/multipattern meters are calibrated along the Zone System with additional metrics overlaying this to assist with "judgement" by the camera (that is, after all, looking through a library of many thousands and thousands of images just like the scene you are viewing).

Otherwise, invest in a high quality meter that you can build your skills around. I don't regard using a digital camera to build knowledge the way to go: it has scant resemblance to the characteristic of film. This is especially true for MF and LF. At a later date, getting the hang of spot metering (something an iPhone does not have -- still!) for very precise analysis of scenes would go a long way toward rewarding you with beautiful, luminous images from MF/LF.